This Core recruits, enrolls and evaluates all subjects entered into the studies of the program project. It uses established clinical protocols at entry and at all assessments to obtain relevant clinical, neurological, and cognitive data to carefully characterize each subject, including for dementia diagnosis and staging. Core data are used by all Cores and projects to explore the correlates of very mild dementia of the Alzheimer type (DAT) in comparison with healthy brain aging. The Core recruits and maintains adequate samples to supply needed subjects for all projects and other cores. In addition to maintaining the longitudinal sample of subjects 65+years (required in all projects) the Core will recruit a sample of subjects at high risk for dementia (Adult Children Study) ages 45-74 to explore antecendents of Alzheimer disease in Project 2 (Novel Biomarkers to Predict Alzheimer's disease), Project 3 (Attention Profiles in Healthy Aging Early Stage DAT)and 4 (Predicting Cognitive Decline in Healthy Elders). For Project 1 (Dementia Assessment in the Community) a shortened dementia assessment is to be tested in the community and this Core will assess subjects using our established clinical protocols to validate the brief instrument. Through its successful voluntary autopsy program, it supplies Core C: Neuropathology with autopsy material and therefore the neuropatholgic diagnoses for the Projects. Core A: Clinical works closely with Core B: Psychometrics to integrate the clinical and psychometric assessments for all subjects and with CoreD: Biostatistics to ensure appropriate data management. The Core supports Core E: Administrative in promoting scientific interactions among all investigators to accomplish the aims of the program project as a whole.